The study did not start as a key co-investigator left the institution.

There are limited evidence-based management options for patients with low-grade oral dysplasia. Despite the risk of malignant transformation, management is frequently limited to risk factor reduction (such as smoking cessation) and clinical surveillance. An intervention for low-grade oral dysplasia which could induce regression or decrease rates of malignant transformation has the potential to be a valuable preventative tool to reduce rates of oral cancer.

The investigators will conduct a randomized clinical trial to investigate if the administration of a probiotic lozenge to patients with low-grade oral dysplasia result in decreased peri-tumoral inflammation as evidenced by impacts on populations of tumor-associated macrophages and tumor-infiltrating lymphocytes, and decreased dysbiosis at the disease site compared with the contralateral normal site. The investigators hypothesize that these changes may increase the rate of clinical regression of these lesions.

Inclusion Criteria:

• Presence of biopsy-proven low-grade or mild oral dysplasia

Exclusion Criteria:

• Active oral cavity malignancy
• Active oral cavity high grade dysplasia
• Currently undergoing chemotherapy or immunotherapy, or have used these agents within the prior 6 months
• History of external beam radiation therapy to the head and neck area
• Diagnosis of HIV with decreased CD4 count and/or detectable viral load
• Current use of systemic or orally absorbed steroids
• Patient undergoing stem cell transplantation
• Patients taking anti-rejection medication after stem cell or solid organ transplantation
• Patients using injectable immunosuppressive drugs for autoimmune disease
• Pregnant or nursing women
• Patients who are hospitalized
• Patients with a heart valve abnormalities or a history of valve replacement or endocarditis
• Patients with active severe acute intestinal disease (active bowel leak, acute abdomen, active colitis) or a history of short bowel syndrome